Volume 4 - Issue 4

4-Nitrophthalic acid - catalyzed Biginelli reaction: One-pot synthesis of 3, 4-dihydropyrimidin-2-(1H)-ones/thiones under solvent free conditions
Dr. Rangappa S. Keri || Dr. Siddappa A. Patil

Abstract: New organic reactions allow chemical transformations which were previously not possible. Therefore, new reactions are important contributions to the progress in the field of organic synthesis. A simple and effective synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives from aldehydes, 1,3-dicarbonyl compounds and urea or thiourea using 4-Nitrophthalic acid as a catalyst under solvent free condition is described. Taking into account of environmental and economical considerations, the protocol presented here has the merits of environmentally benign, simple operation, convenient work-up, short time, good yields, the avoidance of the organic solvent and inexpensive catalyst. The synthesized compounds were characterized by IR, 1H, 13C NMR, MS and elemental analysis.
Keywords: Biginelli reaction; Synthesis; Solvent free; 3, 4-Dihydropyrimidin-2(1H)-ones; Catalyst.

UPQC for Improvement Power Quality
Dr.S Kamakshaiah, Ashwini Kumar

Abstract: This proposed new concept of optimal utilization of a unified power quality conditioner (UPQC) with a power angle control approach is illustrated. The active power control approach is used to compensate voltage sag/swell and is integrated with theory of power angle control (PAC) of UPQC to coordinate the load reactive power between the two inverters. The series inverter of UPQC is controlled to perform simultaneous 1) voltage sag/swell compensation and 2) load reactive power sharing with the shunt inverter. Since the series inverter simultaneously delivers active and reactive powers, this concept is named as UPQC-S (S for complex power). A detailed mathematical analysis, to extend the PAC approach for UPQC-S, is presented in this paper. MATLAB/SIMULINK-based simulation results are discussed to support the developed concept.

Dual power flow Interface for EV, HEV, and PHEV Applications
J Ranga, Madhavilatha

Abstract: This paper on a universal power electronic interface that can be utilized in electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles (PHEVs). Basically, this converter interfaces the energy storage de-vice of the vehicle with the motor drive and the external charger, in case of PHEVs. The proposed converter is operates in buck or boost modes with non-converted voltage and bidirectional power flow

Power Quality & power control Improvement in DFIG Wind Turbine System using RSC& GSC Control system
Abhinav, J Ranga

Abstract: Grid side converter Doubly fed generators' control strategy is proposed. To improve the performance characteristics of DFIG under grid voltage fluctuation. The control strategy is implemented to satisfy grid codes like grid stability, fault ride , power quality improvement, grid synchronization and power control etc. Doubly-fed Induction Generator system uses back-to-back converters in the rotor circuits to meet the necessary needs. Doubly-fed Induction Generator is the most common rotator machine which is used on the grid connected wind energy conversion system for the fulfillment of the system requirement such as grid stability, fault ride through, power quality improvement, and grid synchronization and power control etc. So in order to improve the operation capacity of wind turbine under critical situation, the intensive study of both machine side converter control and grid side converter control is necessary. The machine uses two back-to-back converters. The grid side converter is modeled to control the active power and reactive power independently along with dc-link voltage. This scheme allows wind turbines to remain synchronized to the grid during faults or during voltage sags and swings. The proposed control strategy is confirmed with simulation results in MATLAB/SIMULINK

Voltage sag mitigation in distribution line by using DVR
Ch Sabhitha, J Ranga

Abstract: This proposed controller supplements the voltage-sag compensation control of the DVR for downstream fault current interruption in a radial distribution line . It does not require phase-locked loop and independently controls the magnitude and phase angle of the injected voltage for each phase. Fast least error squares digital filters are used to estimate the magnitude and phase of the measured voltages and effectively reduce the impacts of noise, harmonics, and disturbances on the estimated pharos parameters, and this enables effective fault current interrupting even under arcing fault conditions. The results of the simulation studies performed in the PSCAD/EMTDC software environment indicate that the proposed control scheme: 1) can limit the fault current to less than the nominal load current and restore the point of common coupling voltage within 10 ms; 2) can interrupt the fault current in less than two cycles;3) limits the dc-link voltage rise and, thus, has no restrictions on the duration of fault current interruption; 4) performs satisfactorily even under arcing fault conditions; and 5) can interrupt the fault current under low dc-link voltage conditions

Three-Phase, Four-Wire UPQC Topology with Reduced Switching Losses
M Rakesh, G Kavitha

Abstract: The paper introduces the modified UPQC topology with reduced switching losses. UPQC is a versatile custom power device which consists of two inverters connected back to back and deals with both load current and supply voltage imperfections. It can simultaneously perform as shunt and series active power filters. The series part of the UPQC acts as Dynamic Voltage Restorer (DVR). It is used to maintain balanced, distortion free nominal voltage at the load. The shunt part of the UPQC acts as Distribution STATIC Compensator (DSTATCOM) and it is used to compensate load reactive power, harmonics and balance the load currents there by making the source current balanced and distortion free with unity power factor. The efficiency of the proposed configuration has been verified through simulation using MATLAB/SIMULINK